Slime mold validates efficiency of Tokyo rail network

What do Tokyo commuter-rail designers and the slime mold Physarum polycephalum have in common? The two will build strikingly similar networks.

A Japan-based research team found that if they placed bits of food (oat flakes) around a central Physarum in the same location as 36 outlying cities around Tokyo, the mold created a network connecting the food sources that looked rather like the existing rail system. And when comparable "topographical barriers" were introduced onto the experimental plane, the links were even more similar.

Coincidence? Not at all, concluded the authors of the study, which was led by Atsushi Tero of the Research Institute for Electronic Science at Hokkaido University in Sapporo.